Grids formed by interconnected muntin bars are installed between glass panes in insulating glass units used in windows and doors. Joiners for tubular metal muntin bars are in widespread use in constructing such grids. Some joiners have a square central body and four legs projecting at right angles to each other from the body. The legs telescope into four respective muntin bars and the joiner body forms a visible juncture of the bars. With the advent of contoured muntin bars that may have differing cross sectional shapes and be variously colored, the use of visible joiners has become complicated because of the multiplicity of joiner types required to produce a full range of muntin grid shapes and colors.
Joiners have been proposed that secure muntin bars together while remaining hidden from view when the final grid is installed in a window or door. Hidden muntin bar joiners have reduced the inventory problems associated with visible joiners because the joiner color need not match the muntin bar colors and the joiner shape is not dependent on the muntin bar profile. Nevertheless, hidden joiners have produced inventory problems of their own.
The proposed hidden joiners were constructed so that one joiner section was inserted in a muntin bar and then through a slot in a second transverse muntin bar after which it mated with a second joiner section. The second joiner section was telescoped into a third muntin bar--either before or after mating with the first joiner section--so that the first and third muntin bars were aligned and the second muntin bar extended transversely with respect to them. The ends of the first and third muntin bars were cut to interfit with the second muntin bar and form a grid juncture.
The first and second joiner sections were constructed and arranged so that they could be pushed together and permanently secured. The proposed construction provided a pair of barbed stems projecting from the first joiner section and a female receptacle for the stems in the second joiner section. Consequently, window and door producers were required to inventory multiple joiner sections for every muntin bar size being fabricated into grids.
The present invention provides a new and improved one piece muntin bar joiner that is easily and quickly installed, hidden from view in the assembled grid, and minimizes muntin bar joiner inventory problems attendant fabricating muntin grids.